Recently, an optical fiber having the characteristic of being light weight and not influenced by noise during transmission has been used as a transmission line for light communication and controlling machinery, and an optical switch to be used with the optical fiber has been structured as indicated by FIG. 1 and FIG. 2.
Such an optical switch has the structure that the polished end surfaces 1a, 2a of optical fibers 1, 2 are arranged face to face across gap C and a metallic shielding plate 3 is inserted or removed into/from gap C. In this case, the switch is turned ON by allowing the light beam to pass through the gap C, namely transmitted while the shielding plate is removed as indicated in FIG. 1 or turned OFF by shielding the light beam with the shielding plate 3 inserted into the gap C as indicated in FIG. 2.
However, if the end surfaces 1a and 2a are not arranged face to face accurately, such photo switch results in a large loss of light beam, during ON condition, because the light beam sent from the optical fiber 1 is not effectively transmitted to the optical fiber 2. Thereby, production efficiency has been lowered because it is necessary to accurately match the axes of the optical fibers 1 and 2.